The World Health Assembly is currently debating reform of the World Health Organization’s (WHO) engagement with ‘non-state actors’ – a term that embraces entities or persons that are not governments, such as businesses, charities and NGOs.

One of the issues that has fuelled this debate is a perception that an honest and open exchange between organisations such as the WHO and big business is somehow impossible. It is presumed that the WHO, an agency of the United Nations, needs to be protected from exposure to the perspectives of businesses. Conversely, NGOs, which also seek regular contact with the WHO, are characterised as a group whose advice is bound to be helpful because they are motivated by the public good.

For the seventh year in a row, the 2014 Edelman Trust Barometer showed NGOs remain the most trusted institutions, recording 64 per cent total trust with 23 per cent of respondents saying they trusted them "a great deal". In 20 of the 27 countries surveyed, NGOs were the most trusted, outstripping government (44 per cent), media (52 per cent) and business (58 per cent).

This strength in trust helps explain the openness to NGOs’ evidence in policymaking processes, including at the WHO. But there is a key distinction between an openness to hearing NGO views and a presumption that the evidence they present has a stronger claim to validity due to the moral strength of their mission. NGOs vary in their causes, scale of operation, funding sources and ideological inclinations. The appropriate way to treat evidence from any source – whether NGO, business or any other group – is with a critical eye. This ensures that the best evidence, tested through the fire of scepticism, wins out because it is substantiated, not because of its source.

The same argument should be applied to businesses. Our perspective can be valuable because we have a central role in society and in solving its challenges. Equally, any evidence should be tested on its merits: it should be interrogated and challenged, and where it retains its value it will be helpful for public policymaking.

This is exactly the kind of three-way relationship companies have with policymaking institutions and NGOs in many areas. For example, some major corporations have best-in-class development and environmental initiatives that make absolute business sense for the bottom line and are embedded in the business model, taking their efforts a massive step forward from corporate philanthropy. In many cases, those leading positions have been developed through challenge from and collaboration with NGOs that lead to solutions.

This debate is not new. As political economist John Stuart Mill wrote in 1859: "Since the general or prevailing opinion on any subject is rarely or never the whole truth, it is only by the collision of adverse opinions that the remainder of the truth has any chance of being supplied." Public policy is always improved by a collision of perspectives, in which the best evidence from any source is interrogated and then used where it holds up under that scrutiny. The WHO should hold firmly to that principle.